Fabric compositions comprising cotton and hemp fibers, and methods for their preparation

Abstract

Disclosed are antimicrobial and/or antiviral fabric compositions of cotton and hemp. In some embodiments, the composition also includes ascorbic acid, citric acid, sodium hypophosphite, and/or a mixture thereof. The ascorbic acid may be covalently attached to at least one cellulosic portion of the fabric composition. Also disclosed are methods for preparing such fabric compositions.

We claim: 
     
         1 . A single layered nonwoven fabric comprising about 5% by weight to about 95% by weight non-scoured, non-bleached greige cotton fibers, about 0% by weight to about 95% by weight bleached cotton fibers, and about 5% by weight to about 95% by weight hemp fibers, all weight percentages adding up to 100%. 
     
     
         2 . The single layered nonwoven fabric according to  claim 1 , wherein the fabric comprises about 60% by weight non-scoured, non-bleached greige cotton fibers, about 20% by weight bleached cotton fibers, and about 20% by weight hemp fibers. 
     
     
         3 . The single layered nonwoven fabric according to  claim 1 , wherein the non-scoured, non-bleached greige cotton has a purity level of about 99.9%. 
     
     
         4 . The single layered nonwoven fabric of  claim 1 , wherein the fabric has a density higher than about 30 g/m 2 . 
     
     
         5 . The single layered nonwoven fabric of  claim 1 , wherein the fabric has an increased absorption capacity of about 60% to about 70% when compared with a fabric not comprising non-scoured, non-bleached greige cotton fibers. 
     
     
         6 . The single layered nonwoven fabric of  claim 1 , further comprising ascorbic acid or sodium ascorbate. 
     
     
         7 . The single layered nonwoven fabric of  claim 6 , wherein the fabric comprises about 10 mM ascorbic acid or sodium ascorbate. 
     
     
         8 . The single layered nonwoven fabric of  claim 1 , further comprising ascorbic acid, citric acid, sodium hypophosphite, or a mixture thereof. 
     
     
         9 . The single layered nonwoven fabric of  claim 1 , wherein the fabric comprises about 60% by weight non-scoured, non-bleached greige cotton fibers, and about 40% by weight unbleached hemp. 
     
     
         10 . The single layered nonwoven fabric of  claim 1 , wherein the fabric comprises about 55% by weight non-scoured, non-bleached greige cotton fibers, and about 45% by weight bleached hemp. 
     
     
         11 . The single layered nonwoven fabric of  claim 1 , wherein the fabric comprises about 60% by weight non-scoured, non-bleached greige cotton fibers, and about 40% by weight unbleached hemp, wherein the fabric has been treated with ascorbic acid. 
     
     
         12 . The single layered nonwoven fabric of  claim 1 , wherein the fabric comprises about 55% by weight non-scoured, non-bleached greige cotton fibers, and about 45% by weight bleached hemp, wherein the fabric has been treated with ascorbic acid. 
     
     
         13 . The single layered nonwoven fabric of  claim 11 , wherein the fabrics were treated with 7% (w/v) citric acid, 5% (w/v) L-ascorbic acid, and 4% (w/v) sodium hypophosphite with 0.6% (w/v) 1-hexanol as a wetting agent in ultrapure water using a pad-dry-cure method. 
     
     
         14 . The single layered nonwoven fabric of  claim 12 , wherein the fabrics were treated with 7% (w/v) citric acid, 5% (w/v) L-ascorbic acid, and 4% (w/v) sodium hypophosphite with 0.6% (w/v) 1-hexanol as a wetting agent in ultrapure water using a pad-dry-cure method. 
     
     
         15 . The single layered nonwoven fabric of  claim 11 , wherein the fabrics were treated with 1% (w/v) L-ascorbic acid with 0.6% (w/v) 1-hexanol as a wetting agent in ultrapure water using a pad-dry-cure method. 
     
     
         16 . The single layered nonwoven fabric of  claim 12 , wherein the fabrics were treated with 1% (w/v) L-ascorbic acid with 0.6% (w/v) 1-hexanol as a wetting agent in ultrapure water using a pad-dry-cure method. 
     
     
         17 . The single layered nonwoven fabric of  claim 6 , wherein the ascorbic acid is covalently attached to at least one cellulosic portion of the fabric composition. 
     
     
         18 . An article of manufacture prepared with the fabric composition of  claim 1 . 
     
     
         19 . The article of manufacture of  claim 18 , wherein the article of manufacture is a protective textile. 
     
     
         20 . The article of manufacture of  claim 19 , wherein the protective textile is a surgical arena fabric, a surgical personnel protective garment, a wound dressing, a non-wound patient dressing, a bandage, a gauze, a packing, a mask, or a cleaning material. 
     
     
         21 . The single layered nonwoven fabric according to  claim 1 , wherein the nonwoven fabric is produced by a process comprising:
 (a) preparing needle punched webs of the fibers,   (b) uniformly hydroentangling the webs using a system wherein the system is equipped with one low water pressure jet head that wets the webs on the top face of the webs to form a wetted substrate and wherein the system is equipped with two high water pressure jet heads that subsequently alternatively wets the wetted substrate on either face of the wetted substrate, wherein the system utilizes an about 23 mesh to about 17 mesh screen, and   (c) drying the wetted substrate to form the fabric.   
     
     
         22 . A method for preparing the fabric composition of  claim 1 , wherein the method comprises:
 saturating a fabric composition with citric acid, ascorbic acid, sodium hypophosphite, or a mixture thereof,   padding the saturated fabric composition,   drying the padded fabric composition at a first temperature, and   curing the dried fabric composition at a second temperature higher than the first temperature.   
     
     
         23 . The method of  claim 22 , wherein the ascorbic acid is covalently attached to at least one cellulosic portion of the fabric composition. 
     
     
         24 . The method of  claim 22 , wherein the fabric composition is a cloth, a woven fabric, a knitted fabric, a nonwoven fabric, or a final article. 
     
     
         25 . The method of  claim 22 , wherein the fabric composition is a nonwoven fabric. 
     
     
         26 . The method of  claim 25 , wherein the nonwoven fabric is a single layered fabric or a multilayered fabric. 
     
     
         27 . The method of  claim 22 , wherein the fabric composition is a woven fabric. 
     
     
         28 . A multi-layered nonwoven wound dressing, comprising at least one inner layer containing about 50% by weight to about 95% by weight non-scoured, non-bleached greige cotton fibers and about 5% by weight to about 50% by weight hemp fibers, all weight percentages adding up to 100%, and at least one outer layer containing about 5% by weight to about 95% by weight non-scoured, non-bleached greige cotton fibers, about 0% by weight to about 95% by weight bleached cotton fibers, and about 5% by weight to about 60% by weight hemp fibers, all weight percentages adding up to 100%.